Li H.,University of California at Los Angeles |
Monien B.H.,University of California at Los Angeles |
Monien B.H.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke |
Fradinger E.A.,University of California at Los Angeles |
And 3 more authors.
Biochemistry | Year: 2010
A key event in Alzheimer's disease (AD) is age-dependent, brain accumulation of amyloid β-protein (Aβ) leading to Aβ self-association into neurotoxic oligomers. Previously, we showed that Aβ oligomerization and neurotoxicity could be inhibited by C-terminal fragments (CTFs) of Aβ42. Because these CTFs are highly hydrophobic, we asked if they themselves aggregated and, if so, what parameters regulated their aggregation. To answer these questions, we investigated the dependence of CTF aqueous solubility, aggregation kinetics, and morphology on peptide length and sequence and the correlation between these characteristics and inhibition of Aβ42-induced toxicity. We found that CTFs up to 8 residues long were soluble at concentrations > 100 μM and had a low propensity to aggregate. Longer CTFs were soluble at ∼1-80 μM, and most, but not all, readily formed β-sheet-rich fibrils. Comparison to Aβ40-derived CTFs showed that the C-terminal dipeptide I41-A42 strongly promoted aggregation. Aggregation propensity correlated with the previously reported tendency to form β-hairpin conformation but not with inhibition of Aβ42-induced neurotoxicity. The data enhance our understanding of the physical characteristics that affect CTF activity and advance our ability to design, synthesize, and test future generations of inhibitors. ©2010 American Chemical Society.
Steinbrenner H.,Friedrich - Schiller University of Jena |
Brigelius-Flohe R.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Aktuelle Ernahrungsmedizin | Year: 2015
Selenium is an essential trace element and micronutrient for humans that exerts most of its biological actions through selenoproteins, which have the rare amino acid selenocysteine in their active centre. Several selenoproteins such as glutathione peroxidases (GPx) and thioredoxin reductases (TrxR) have antioxidant and redox-active functions. Assumed (and in part controversially discussed) beneficial effects of selenium on human health include the prevention of some types of cancer, slower progression of autoimmune thyroid diseases, adjuvant therapy of viral infections and support of immune, reproductive and cognitive functions. In the diet, selenium is mainly present in form of the amino acids selenomethionine and selenocysteine, while dietary supplements may also contain higher amounts of inorganic selenium compounds such as sodium selenite and selenate. Recently, the European Food Safety Authority (EFSA) has set the dietary reference value for adequate selenium intake of adults to 70μg/day, as did the German Society for Nutrition (DGE) with 60μg/day for women and 70μg/day for men. These values are based on the requirements to saturate blood levels of the selenium transport protein selenoprotein P (SePP1). Many Europeans - including Germans - ingest less selenium; however, selenium deficiency is not a general problem. On the other hand, selenium supplementation beyond the doses required for SePP1 optimisation may not provide additional health benefits and, according to some studies, may even provoke adverse side effects. Therefore, dietary selenium supplementation is not recommended for healthy people in general. Persons who wish to take selenium-containing dietary supplements should have measured their plasma/serum selenium or SePP1 levels first. Selenium supplementation might be useful for persons with low selenium status and/or increased needs of selenium. © 2015 Georg Thieme Verlag KG Stuttgart.
Schulze M.B.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Diabetologe | Year: 2012
Dyslipidemia in diabetes is characterized by low high-density lipoprotein (HDL) cholesterol, high triglyceride levels and higher concentrations of atherogenic lipoprotein molecules. Various interventions are of importance in the nutritional therapy of dyslipidemia. An increased intake of unsaturated fatty acids from vegetable oils at the expense of saturated fatty acids lowers low-density lipoprotein (LDL) cholesterol. Trans-fatty acids (food sources: fat spreads and foods with partially hydrogenated fat, fried foods, fat-rich baked goods and sweets) cause an even more etrimental lipoprotein profile compared to saturated fatty acids and their intake should be limited. Significant reductions of LDL cholesterol are also achievable by fiber-rich foods and foods enriched with plant sterols and stanols. A reduction of body weight, an increase in physical activity and a limitation of alcohol consumption to moderate amounts are effective interventions to control triglyceride and HDL cholesterol levels. Triglycerides can also be reduced by supplementation with long-chain ?3 fatty acids (fish oil). Higher proportions of dietary carbohydrates cause higher triglyceride levels, therefore, moderation of carbohydrates in favor of unsaturated fatty acids can be an effective dietary strategy and the major focus is to limit the consumption of foods and beverages with added saccharose or fructose. © Springer-Verlag Berlin Heidelberg 2012.
Carl Arthur Scheunerts experiments on human nutrition, 1938-1943: Boundary transgressions of a scientist under National Socialism [Carl Arthur Scheunerts Ernährungsversuche am Menschen 1938-1943: Grenzüberschreitungen eines Wissenschaftlers im Nationalsozialismus]
Joost H.G.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Medizinhistorisches Journal | Year: 2012
Carl Arthur Scheunert (1879-1957) was a German scientist who supervised several studies with prisoners that were designed to assess the optimal vitamin and nutrient supply, and were conducted by his associate Karl-Heinz Wagner (1911-2007) from 1938 to 1943. This contribution describes the aims, results and conclusions of Scheunert's research 1923 to 1945 in comparison with the national and international vitamin research and its consequences for public health measures. Conditions and results of the human experiments are reconstructed and compared with similar studies performed in other countries. Burden as well as health risks for the study participants are assessed. In addition, it is discussed whether general rules for human experimentation were followed (e.g. informed consent and minimizing of health risks). Although the available documents support the conclusion that no deaths or lasting injuries were caused, the experiments violated ethical standards, in particular because of the conditions in the Waldheim prison including progressive deterioration of nutrition and health. © Franz Steiner Verlag, Stuttgart.
Using dietary fibre to counteract excess weight: The influence of a fibre-rich diet on the obesity risk [Mit Ballaststoffen gegen Ballast: Einfluss einer faserreichen Kost auf das Risiko von Adipositas]
Schulze M.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Aktuelle Ernahrungsmedizin | Year: 2014
The question of whether an increased intake of dietary fibre lowers the risk of obesity has been investigated in many studies. Prospective cohort studies and intervention studies have yielded particularly meaningful results. Even though the results are heterogeneous and make it difficult to reach unequivocal conclusions, trends can still be noted. Especially water soluble fibres with a high swelling capacity increase the feeling of saturation in the short-term. Most prospective cohort studies have indicated that the long term risk of weight gain falls with an increase in dietary fibre intake, but to a very moderate degree. The effects on body weight are not limited to certain dietary fibres but apply to all of them. The currently available data suggest the conclusion that a sufficiently high intake of dietary fibre in the form of wholemeal products, fruit, and vegetables is to be recommended. It is likely that such an intake will have a positive effect on body weight.©Georg Thieme Verlag KG Stuttgart.
Molecular basis of the relationship between nutrition and health: What can basic research contribute to prevention and therapy? [Molekulare grundlagen des zusammenhangs zwischen krankheitsentstehung und ernährung: was kann die grundlagenforschung für prävention und therapie leisten?]
Joost H.-G.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Aktuelle Ernahrungsmedizin | Year: 2012
Experimental research identifies mechanisms, susceptibility genes and biomarkers for nutrition-associated diseases, thereby contributing to the validation and improvement of prevention and intervention strategies. At present, the personalization of nutritional recommendations is not possible with genetic marker but can be guided by conventional risk factors and biomarkers. However, genetic markers allow the inference of causality of associations between biomarkers and disease endpoints by Mendelian randomization. In the future, genetic markers may also help to establish causality of associations between nutrients and disease endpoints. In addition, elucidation of the genetic basis of nutrition-associated diseases can provide biological plausibility of preventive and therapeutic strategies. © Georg Thieme Verlag KG.Stuttgart · New York.
Blaut M.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Aktuelle Ernahrungsmedizin | Year: 2015
The intestinal tract is home to a complex microbial community (microbiota), which is characterized by large inter-individual differences. One of the main components of dietary fiber are indigestible polysaccharides, which in dependence of their physicochemical properties affect gut physiology either directly or by way of the intestinal microbiota. Indigestible carbohydrates are the main substrates of intestinal bacteria, which convert them mainly to short-chain fatty acids as well as hydrogen, carbon dioxide and methane. Short-chain fatty acids not only provide energy to the host but also possess regulatory functions. They influence the lipid metabolism in the liver and the excretion of hormones, which affect gastrointestinal passage, insulin sensitivity and satiety. Overall the role of short-chain fatty acids in the development of obesity and diabetes is not completely understood. © Georg Thieme Verlag KG tuttgart New York.
Body mass index, waist circumference, and the risk of type 2 diabetes mellitus: Implications for routine clinical practice [Body-mass-index, taillenumfang und risiko für diabetes mellitus typ 2: Konsequenzen für den medizinischen alltag]
Feller S.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke |
Boeing H.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke |
Pischon T.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Deutsches Arzteblatt | Year: 2010
Background: Current guidelines for assessing the risk of developing type 2 diabetes mellitus (DM) recommend using the patient's body-mass index (BMI) as a primary measure. Waist circumference measurement is recommended for overweight or obese patients only (BMI ≥ 25). Methods: We studied the interaction between BMI and waist circumference with respect to the risk of developing type 2 DM in a cohort of 9753 men and 15 491 women, aged 35 to 65, who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam. The statistical analysis was performed with multivariable- adjusted Cox proportional hazard regression. Results: During a mean follow-up interval of 8 years, type 2 DM was newly diagnosed in 583 men and 425 women. A statistically significant interaction was found between BMI and waist circumference with respect to the risk of type 2 DM (p<0.0001). The positive association between waist circumference and diabetes risk was stronger in persons with lower BMI. The relative risk (RR) of developing type 2 DM among persons of low or normal weight (BMI<25) who had a large waist circumference was at least as high as that among overweight persons (BMI 25-29.9) with a small waist circumference: for the first case, the RR was 3.62 [1.67-7.83] in men and 2.74 [1.52-4.94] in women; for the second case, the RR was 2.26 [1.51-3.37] in men and 1.40 [0.61-3.19] in women (the figures in square brackets are 95% confidence intervals). These relative risks were calculated in comparison to the risk among persons of low or normal weight (BMI<25) with a small waist circumference. Conclusion: These findings imply that the waist circumference is an important additional piece of information for assessing the risk of type 2 DM, particularly among persons of low or normal weight.
Joost H.-G.,Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke
Diabetes Aktuell | Year: 2014
According to the currently available data DPP-4 inhibitors are safe and well tolerated antidiabetic agents that are superior to the sulfonylureas in terms of the criterion safety because of their markedly lower risk of hypoglycemia. In addition, they are better tolerated than metformin, which often induces undesired gastrointestinal side effects. Their cardiovascular safety has been unambiguously demonstrated. However, it is still not certain whether or not they can antagonize the macro- and/or microvascular complications of diabetes mellitus. Interactions with other drugs very rarely, if at all, lead to complications (angioedema in combination with ACE inhibitors, competitive inhibition of the degradation of CYP3A4 substrates). Reports or fears that the risk of pancreatitis is increased by DPP-4 inhibitors have not been confirmed. Even if very rare complications in a few sensitive subjects cannot be excluded, this group of substances represents the best tolerated antidiabetic active principles currently available.
Deutsches Institute For Ernahrungsforschung Potsdam Rehbrucke | Date: 2010-09-27
The present invention relates to agonists of the human bitter-taste receptor hTAS2R7 and its role in bitter taste transduction. The invention also relates to assays for screening molecules that modulate, e.g. suppress or block hTAS2R7 bitter taste transduction or bitter taste response.